Saw swaging, shaping, and grinding machine.



SAW'SWA-GING, SHAPING, AND'GRINDING MACHINE. 1 APPLICATION FILED IuNE4, I9'I4. 9 9

Ptend Apr. I8, 1916.

J. F. PB IBNow. SAW SWAGING, SHAPING, AND GRINDING MACHINE.

APPLICATION FILED JUNE 4,1914. I

Patented Apr. 18, 1916.

I4 SHEETS-SHEET 2- y J. F. PRIBNOW.v .SAW SWA'GING, SHAPING, AND GRINDING MACHINE.

11.1111111611 Apr; 18, 1916.

I4 SHEETS-SHEET 3- J. F.' PRIBNOW. -SAW SWAGING, SH APIN", AND GRINDING MACHINE.

. APPLICATION FILED JUNE 4, I9I4- 1,179,556. Patented Apr. 18, 1916.-

I4 SHEETS-SHEET 5- III All /7//0/l if;

www

1. F. PRlBNoW. SAW SWAGING, SHAPING, AND GRINDING MACHINE.

APPLICATION FILED JUNE 4, I9I4. I

- Patented Apr. 18, 1916.

I4 SHEETS-SHEET 7 SAW SWAGING,SHAPINGVAND GRINDING MACHINE.'

APPLICATIQN FILED JUNI-1K4. 1914.

Ptented Apr. 18, 1916.

I4 SHEETS-SHEET 8.

l III III.

1. F.- PRIBNow. `SAW SWAGING, SHAPING, AND GRINDING MACHINE.

APPLICATION FILED JUNE 4, I9I4.

Patented 18, 1916.

I4 S SHEET 9.

J. F. PRIBNOW.

sAw SWAGING, SHAPING, AND GRINDING MACHINE.

APPLICATION FILED JUNE 4,1914.

Patented Apr. 18, 1916.

14 SHEETS-SHEET l0.

Ifig. 12

Munk-Y C@ MINIMA' J. F. PRIBNOW. SAW SWAGING, SHAPING, AND GRINDING MACHINE.

'APPLICATION FILED JUNE 4,1914.

Patented Apr. 18, 1916.

I4 SHEETS-SHEET Il.

1. F. PRIBNOW.

SAW SWAGING, SHAPING, AND GRINDING MACHINE.

APPLICATIQN FxLED JUNE 4.1914.

i4 SHEETS-SHEETI 2.

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WIT/VESSES: l /IVVE/VTOR J. F. PmBNow. SAW SWA'GING, SHAPING, AND GRINDING MACHINE.

APPLICA'I'ION` FILED JUNE 4. |914. Patented Apr. 18, 1916.

fllllllulllf 4 J. F. PRIBNOW.

SAW SWAGING, SHAPING, AND GRINDING MACHINE.

Y APPLICATION FILED JUNE 4.41314.

1, 1 79,556. Patented Apr. 1,8, 1916.

I4 SHEETS-SHEET I4.

JOHN F. PBIBNOW, F MELLEN, INDIANA.

saw' sWAGINe, sHAPING, AND GnINDINe Madama.

To all lwhom t may concern Be it known that I, JOHN F. PRrBNow, a citizen of the United States, residing at Mellen, in the county of Ashland andState of Indiana, have invented a new and useful ing, and grinding saw teeth, particularly of Saw Swaging, Shaping, and Grinding-Machine, of which the following is a specification.

It is the object ofv my invention to provide a machine for automatically swaging, shapband saws; to make such machine adjustable for diEerent shapes and sizes of saws and saw teeth; to provide for grinding the entire surface of the saw tooth and maintaining an even wear' on the grinding surface of the grinding wheel; to provide a feeding device which tends to lessen any inequalities which may exist in the spacing of the saw teeth; toprovide an adjustable control cam for the grinding apparatus, whereby the grinding actionvon different parts of the saw tooth may be accurately controlled independently; to provide a feeding device which pulls the: -saw instead of pushing it, thereby avoidingl any inaccuracies in feedlng -such as might be due to buckling of the feeding device; to provide rapidly acting swaging and shaping deviceswhich act accurately on the saw teeth as the saw is fed along; to provide a floating grinding wheel, capable of yielding axially in either direct1on if'required to do so by reaction from the saw teeth being ground; to provide a 5 connection' between the swaging and shaping devices whereby they may readily be ad- )usted relatively to each other for different Saw tooth spacings and whereby they automatically adjust themselves relatively to each other to rovide for accurate action on the saw teeth, these two devices acting simultaneously; and to provide a back feed for feeding properly the opposite side of the band saw from that on which the swaging, shaping, and grindingdevices are operating, and to make such back feed operative when any of .such devices are working, whether or not the others are working.

The accompanying drawings illustrate my invention.

In these drawings, Figures 1, 2, and 3 when placed side b y side together provide a plan view' of a machine embodying my invention; Figs. 4, 5, and 6 lwhen placed side by side together furnisha front elevation of such machine; Fig. 7 is an end el."

Specification of etters Patent.

' Patented Apr. 18, 1916.

Application led June 4, 1914. Serial No. 842,876.

v'ation of such machine, taken from the left hand end; Figs. 8 and 8a illustrate the back feed; Flg. 9 is a plan view of the swaging devlce; Fig.. 10 is a front elevation of the swaglng device; Fig. 11 is a section through the swaging device, taken substantially on the line 1-111 of Fig. 9; Fig. 12 is a planv v iew of the shaping device; Fig.. 13 is a section on the line 13 -13 of Fig. 12; Figs. 14:, 15, and 16 are respectively a plan, an end elevation, and a longitudinal section through the mounting -for the shaping device; Figs. 17 and 18 are respectively a longitudinal section and a plan of a modified form 'of mounting for the shaping device; Figs. 19 and 20 are sectional views, on the line 19-19 of Fig. 20 and the line 20-20 of Fig. 19 re'- spectively, showing the mounting for the feed fingers of the grinding device; Figs. 21, 22, 23, and 24 are respectively a'plan view, an elevation'frorn the left hand end, a section on the line 23-23 of Fig. 21, and a section 'on the line 2li-24: of Fig. 21, `showing the construction of the feed fingers for' the grinding deviceVFigs. 22 and 24 also showing the'frame ofl the machine in sec.-

tion; Fig. 25 is a plan view of the swagingv and shaping end of a machine embodying a modifedform of my invention;Fig. 26is i a front elevation of the part of the machine shown in Fig. 25; Fig. 27 is an end elevation of such machine, taken from therighthand end; Fig. 28 is a detail of the adjustable cam for the grinding device; Fig. 29 is a front elevation of the mounting for the grinding device; Fig. 30 is a section on the line 30-30 of Fig. 29; and Fig. 31 is a section on the line 31-31 of Fig. 29.

The main frame 30 is provided at the top and in front with a fixed clamping plate 31, extending the full length of the machine,

and coperating` with this is a movable clamping plate 32, also extending the full length of the machine, and carried by arms 33 pivoted on separate pivots 33.and `extending downward beyond such pivots, the arms 3 at their lower endsv conveniently being provided with leaf springs 34, adjustable by screws 34', which springs cooperate with cams 35 carried by levers 36, the two levers 36 being operable independently of each other for moving either end of the movable clampingy plate 32 into clamping position. The clamping'plates 31 and 32 receive between them that part of the saw S which is to be operated on, and the The part of the band saw opposite thatv being operated on by the machine, is suitably supported so that it can slide either in the rear of or in front of the machine, and is fed bya finger 40,-here called the back feed finger because this part 'of the 'saw is usuallylbehind the machine, which feed Enger is carried by an arm 41 on the rear end of a rock shaft 42, the forward end of which is provided .with an`arm 43 vwhich at its free Vend carries a roller 44 operatable by a cam 45 splined on a shaft 46 and movable along suchshaft into and out of position to operate the arm 43. This movement of the cam 45 is obtained by means of suitableconnections to the arm 47 'on a 'rock shaft 48 having an operating handle 49, said shaft 48 also having an arm 50 which'operates a movable clutch member 51 to clutch together one end of the shaft 52 of the main operating motor 53 and a shaft 54 at the same time that it moves'the cam 45 into position to operate the arm 43.` The shaft 54 drives the shaft 46 through any suitable connection, such as worm gearing 55. The clutch 51 andthe cam 45 are placed in operative position when it is desired to grind the saw teeth. T he opposite kend of the motor shaft 52 may be connected to a shaft 60 by a movable clutch member G1, operable by an arm 62 on a shaft 63 which can be rocked'by an E operating handle 64, the shaft 63 also being connected by suitable connections to cam 65 to shift it along a shaft 66 on which it is splined into and 'out of position to operate aroller 67 carried by slide bar 68 pvotally connected at one end to the arm 43, conveniently by the same pivot which carries the roller 44. The shaft 60 drives the shaft 66 through any suitable gearing, such as worm gearing 69. The clutch 61 and the cam 65 are placed in operative position at the same time, by the operation of the handle 64, when it is desired to operate the swaging and shaping devices. Thus the back feed is operated by either the cam 45 or the 1cam 65, when either the grinding or the swaging and shaping devices are operating, the rock shaft 42 being turned in a counter-clockwise direction (Fig. 5) by either of these cams and being suitably returned in the opposite direction, as by 'a weight 70, said return movement being adjustable by a screw 71 cooperating with the end of the slide rod 6.8 to vary the throw of the back feed finger 40 for different saws The feed finger 40 is conveniently provided with a joint 72, by reason of lwhich it can be thrown to inoperative position, and also preferably has a saw-spanning yoke 73 which carries a pin 74 directly engaging the saw teeth. The shaft 66 also carries cams 75, 76, and 77, and these three cams coperate with rollers carried by arms 78, 79, and 8O respectively, these three arms conveniently all being pivoted independently of each other on the same pivot pin 81 and-the arms 78 and 80 extending upward beyond such pivot pin. The arm is biased in a counter-clockwise direction around its pivot pin by an adjust.- able spring 82 to draw the roller on the lower end of such arm against the surface of the cam 77, and the arms 78 and l7 9 are interconnected bv an adjustable spring 83 which drawsv both of them toward their cooperating cams 75 and 76, the roller on the arm 79 engaging the'high and low points on its'coperating cam 76 at the times when the roller on the arms 78 Aengages the low and high points on its coperating cam 75, so that there is a semi-positive though yieldably returning action of the arm 78 in the opposite direction from that in which it is moved. by its cam. Pivotally mounted on the upper end of the arm 78 are arms 85 and 86, which extend to the left and to the right respectively (as seen in Fig. 6) and carry the swaging device 87 and the shaping device 88 respectively.

The swaging device, which will be described more in detail later, has a clamping arm 89 and a swage-operating arm 90, which are connected by adjustable links 91 and 92 respectively to the upper ends of two arms 93 and 94 respectively, such arms being pivoted at intermediate points, conveniently on a common pivot pin 95, and at their lower ends-being provided with rollers which cooperate with cams 97 and 98 respectively, these two cams being mounted on a shaft 99 connected by suitable gearing 100 to the shaft 66. The cams 97 and 98 push the lower ends of the arms 93 and 94 to the right, such arms being returned to the left by adjustable springs 101 and 102 respectively, and also being positively returned during certain parts of their motions by internal .cam sections 103 and 104 respectively carried by the cams 97 and 98. The connection between the link 91 andthe upper end of the arm 93 is a yieldable one, so that there may be yielding when the clamping arm 89 of the swaging device is operated to its limit of movement, this yielding device comprising a yoke 105 pivoted to the upper end of the arm 93 and having its two arms perforated to receive the left hand end of the link 91, such link ing ^ wise being surrounded between the two arms of the yoke by a compression spring 106 which acts between the right hand arm of the yoke and a collar 107 fixed on the link.

The swaging device is illustrated in detail in Figs. 9, 10, and 11. The'arm 85 terminates at its left hand end in a pair of arcshaped members 11'0, which have slots 111 through which bolts 112 extend for adjustably holding' in place two supporting annuli 113. These annuli furnish bearings for the ends of-a swage block 114, which has an enlarged middle part which lies between -the twoannuli 113 and projects out beyond the circumference of its bearing portions.

'A pin 115 isvfixed in the periphery of the swage block A114 at a suitable place, and projects out through a slot 116 .in one of the annuli 113, said slot being sufficiently longer .than the diameter of the pin 115 to permit a slight relative turning movement between the swage block ,and the annuli. This turnmovementof the swageblock in a clockf direction is limited by the lower edge of the slot 116, while its movement in the other direction is adjustably limited by a screw 117 carried by an arm 118 projecting from one of the anxiuli 113. The swage block 114 is cut away on its lower side, as indicated in Fig. 11, to provide a slot into which the saw may project. The clamping 4members 119 and 120 project .into this slot from opposite sides in position tograsp the saw substantially atthe base of the tooth which is being swagd. The clamping mem-l ber 119 is pushed inward by a screw 121 to which tlfe arm 89 is fixed, so that said clamp-, ingmember is clamped and released by the operation of said arm upon theswinging of the lever 93, and the clamping member `120 is adjustably pushed inward'by an`adjusting Screw 122.

' The swage block 114 is bored obliquely to receivea swage anvil 123, which fits freely in such bore and is adjustably fed downward by a screw 124 which-forms an abutment against which the upper end ofthe swage anvil bears. f When properly adjusted, the swage anvil 123 is clamped in adjusted position by a clamping screw 123', the head of which is shown as countersunk in the front face of the swage block 1-14 to allow a '114 and projects outward therefrom on the forward side, where itis `attached to the 'swage-operating arm 90. .Thusthe swage shaft 126 is turned by the operation 'of the "glever 94, thereby forcing the roller 125 tof ward the lower end of the' swage anvil 123,

or allowing it to recede therefrom, to effect time/happens to be between the swage anvil and the roller. The swage shaft 126 is cut -away in the plane of the saw, and of the saw-receiving slot in thel swage block, be-

tween the roller 125 and the swage anvil 123, to allow these 'to coperate on the saw tooth; and` is also almost completely cut away in the same plane below the roller 125,

leaving only a crescent portion 127 for in-v terconnecting the two parts of the shaft 126 on opposite sides of the'saw-'receiving slot,

thereby permitting the shaft `to pass over the successive saw teetlfwith less rise. and fall and therefore with less force inthe striking v of the parts on the saw. The swag'eshaft 126 is held in place against accidental' axial movement by a pivoted arm 126', which normally projects into a vgroove in the swage shaft but can be turned aside to permit such swage shaft to be withdrawn. e

. TheV feeding of the saw during .the swaging operation is accomplished by the engagement of the saw tooth with the roller 125 as the swaging device 87 is reciproeated by the rocking of the lever 7,8, so that the feedingV itself forces the saw tooth point firmly up between the roller 125 and the swage anvil 123. The various cams on shafts 66 and 99 are so arranged relatively to one another that during the reciprocation of the swaging between the saw and the swage device dur- A ing the swaging operation and during the movement of the sawto the right while still allowing the two to move together to th e right, this clamping being in a clockwise d1- rection to bring the @in 115 to the lower edge of the slot 116, after which the swage shaft 126 is operated in a counter-clockwise direction to squeeze the point of the saw tooth between the roller 125 and the swage anvil 123,A during the latter part of which move-Y ment of the swage shaft the pressure suciently overcomes the pull of the -arm 89 to cause the swage block in its entirety to be moved in a counter-clockwise Vdirection until the pin 115 engages the stop screw 117, thereby producing a drawing out of the saw tooth between the roller 125 and the swage anvil 123. All this Vtakes place while the saw is being moved to the right a distance -equal to the spacing between adjacent teeth,

at` the conclusion of which movement the proper cams quickly return the shaft 126 in counter-clockwise direction to release the saw, whereupon the swaging device 87 moves in its entirety to the left to the next saw tooth. The length of reciprocat'ion of the swage device and also of the shaping device -a clockwise direction and the arm 89 in a. I

the swaging of-the saw to/othwhich at thatV is adjusted by a screw 128 which coperates 130 with the arm 78 to limit the counter-clockwise motion of the latter. The throw of the swage-operating arm 90 in the swage-releasingdirection is limited by a stop pin 129,

. thus supporting such arm.

The shaping device 88 is directly carried by a slide bar 14'0, which is slidably mounted on the arm 86 so as to slide longitudinally therealong. The slide bar 140 is biased t'o theright along the arm 86, by an adjustable Spring 141, its movement in this direction being limited by a suitable stop. One vform of this stop, shown in Figs. 14, 15, and 16, comprises a flanged screw 142 mounted in the -slide bar 140, the flange of which engages the left hand edge of an abutment 143 provided on the arm 86 when the movement of the slide bar 140 to the right along the arm 86 reaches the desired limit of movement. The turning of the screw 142 adjusts its iiange, theu socket ,for such screw 142 being slotted so that a clamping screw 144 may clamp such screw in adjusted position.

Another form of limiting device for theV movement between the arm 86 and the slide bar 140 is shown in Figs. 17 and 18, in which device the arm 86 and the slide bar 1 40 are providedwith cross pieces 145 and 146 respectively, the latter overlying the former andbeing provided with a number of slots 147 throughany one of which a screw 148 lcan be inserted into the proper one of a number of coperating screw holes 149 in the cross piece 145, the slots-147 and the screw holes -149 being properly spaced vfor the l'dilerent standard saw tooth spacings, and one slot and its coperating screw hole serving for a number of spacings.

The end of the Slide bar 140 terminates in alpair of arc-shaped members 155, provided with slots through which project headed.

screws 156 which adjustably fasten the shaper head 157 againstthe inside surfaces` of said members 155. The Shaper head 157 has-a cylindrical surface at its ends, where it coperates with the members 155, but at its middle portion is enlarged to project outcward between such member so that movement of the Shaper head crosswise of the slide bar 14() is prevented. ,The Shaper head has a projection -t`o the left, which is per" orated to receive the lower and up ertooth gages 158 and 159, which have a ead and socket connection160 with each other so that they may be moved together longitudinally while permitting the upper tooth gage to swing about the head and. socket connection a small distance vertically The two tooth gages are adjustable longitudinally together by a screw 161, which is clamped in adjusted position by a clamping screw 162. ,A pin 163 bears slidably against the upper slrface of the upper tooth gage 159, and an' eccentric portion 164 of a cam shaft 165 bears against the upper end of said pin 163 to force the latter downward when the shaft is rotated. A removable screw 166 permits access to this eccentric portion 164 and to the pin 16e.

The shaft 165 is connected-by gearing 167 to a right and left screw 168, the right and left hand threads on which coperate with internal threads on slide blocks 169 and 170 respectively, said slide blocks being mounted to slide in the Shaper head 157 along the screw 168. The Shaper head is 'cut away at its lower portion, to provide space for the saw and for shaper jaws 171 and 172, which are carried respectively by the two slide blocks 169 and 17 0,-but in order to hold these slide blocks in place the shaper head is provided with hooked guide fingers 173 which take in recesses in the slide blocks 169 and 170. The Shaper jaws are clamped in place in the recesses provided for them in the slide blocks 169 and 17 0 by clamping plates 174 and clamping screws 175, and are .adjustable longitudinally by adjusting screws 176, which have flanges bearing against the outer ends of theshaper jaws. rlhe ends of these Shaper jaws work against the sides of thethe Shaper head 157 by a clamping'screw 179.

The screw 168 is providedwith an operating arm 180, which is connected by a link 181 to the upper, end of the /lever 80, such connec ion being a yieldable one here shown as comprising a'yoke 182 pivoted on the lever 80 and having arms'between which is.l

located a compression spring 183 and a collar 184, the latter. being fast to the link 181 and the formery bearing against such collar and one of the arms ofthe yoke 182'.

Durin oper-ation, the shaper 88and vthe swage '8 work at substantially the same time,as the saw is being moved to the right. bythe swage, the yielding permitted by the connection between the arm 86 and theslide bar 140 permitting the 'Shaper to adjust itself to the teeth forl slight inequalities m; spac-' ing. 'As the swage starts te move they saw to the right, the saw tooth to` be'shaped is l forced. up between the-tooth gages 158 and' 159, and the lever'80 is swung in a clockwisev 55 v conveniently a suitably mounted nut, so that it is adjustable longitudinally of the motor shaft to vary the compression of thespring direction sufciently rapidly sc that the arm vals 212 between 180and screw 168 are. swung 1n a counterclockwise direction relatively to the Shaper head 157, thereby forcing the shaper jaws 171 and 172 toward veach other to'give the proper shape to the side of the tooth,` the gearing 167 at the same time causing the eccentric 164 and pin 163 to push downv the upper tooth gage 159 against the back of the tooth point, to maintain it in proper shape. The movement of the jaws 171 and 172 toward each other and' of the upper tooth gage downward' is completed and the shaping of the tooth finished during each movement of the saw to the right, and lever 80 is swung quickly in a counter-clockwise direction to release the saw from the Shaper jaws and the tooth gage upon the completion of such movement of the saw tothe right. i

The links 91," 92, and 181 are all preferably made adjustable in length,'conven1ently by being made of two parts connected by a screw and slot connection 190, and each of these'links preferably engages its arm 89, 90, or 180 (as the case may be) by a hook 191, whereby the link and arm may be readily disconnected.

In order to provide for throwing the swage and Shaper separately into and out of action` as desired, while st ill allowing them to be reciprocated, slides 1-93 and 194 are provided, these 'slides being movable vertically, as by a bell-crank lever 195 connected to the vertical supporting rod for the slide V193, or by a lever 196 connectedeto the verti# cal supporting rod for the slide 194 and movable to a position above or below a holding stop 197, these slides 193 and 194 when in their lower positions permitting the swage and the shaper respectively to operate on the saw teeth. but when raised lifting the swage and the shaper respectively above and clear of. the saw teeth. When the swage -is lifted, the lower part of one of the annuli 113 rests on the slide 193, and\ when the Shaper is lifted the shoe 198. attached to it rests slidably upon the slide 194. l'

The grinding is done at the left hand end of the machine. The grinding lwheel 210 is preferably mounted directly on the inclined shaft of a motor 211, such shaft at its upper end being provided-with a lcollar on the frame of the motor 211 is a compression spring 214. The abutment 213 is 214, and by proper` adjustment will provide a slight space 215 between the hub of the grinding wheel210 and the adjacent shaft bearing.l This permits the grinding wheel 210 to yield in either direction along its axis, in one case against gravity and inthe other case against the spring 214, so that -216 carried by'the'free AThe support and extends through f shaped, being which and an abutment 213 causes the grin vby a number of clamps 233 it'can accommodate itself to any inacuracies in the relation between the tooth shape and its own movement.

The-motor 211 is mounted on a support end of a pivoted arm 217 having its pivot 21.8 adjustable along a slot 219 by means of a screw 220. 216 comprises two slidingly interitting parts 350 and`351, fittingA together on a straight dovetail slideway 352, .which is inclined as appears from Figs. 4 and 29. The part 350 is provided with a shelf 353 on which the motor 211 is mounted. The two parts 350 and 351 are relatively adjustable along the slideway -352 bya screw 354; which extends parallel to the slideway352 a threaded cross 'piece 355 on the part 351, provided at this upper end with a bevel gear 356 which engages with a bevel gear 357 on a forwardly extending shaft 358 mounted in the part 350 and provided at its forward end with an operating hand wheel 221. By turning the hand wheel 221, the part 350 .and the .motor 211 are adjusted along the slideway 352 relatively to the pant 351. The part 351 has slide lugs 360 which vfit into curved slide grooves 361 in the end of the arm 217, whereby the support 216 as a unit may be adjusted on the end of the arm 217 in such grooves. In this way, the angle of the grinding wheel varied. Suit ble'clamping screws 362 are provided for clamping the lugs 360 1n desired position in the grooves 361.- rIfhe slide grooves 361 and the slot 219 are .arc-

drawn about the point of the saw tooth/ being operated on' as a center when the arm 217v is in a given position, so that adjustment of the parts along such curved slide grooves 0r along such slot-will be an arcuate adjustment around the point of such 'saw tooth. The arm 217 is connected by a link 222 of adjustable length to an arm 223, pivotally supported at its left hand end on a linkl 224 in turn carrled by the frame 30. The .right hand end of the arm 223 is pivotally connected to a sleeve 225 on a vertical shaft 226, the sleeve and shaft being vertically movable together, and the shaft being splined within the hub of a bevel gear 227 mounted for rotation only in a Xe'd bearing 228 and meshlng wlth a bevel gear 229 on the shaft 46. The upper end of the vertical shaft 226 has fixed thereto an arm 230 carrymg'a roller 231 at its outer end, and this roller rides on a flexible adjustable cam 232 to cause the shaft 226 to be moved up and down. This in turn, through the mechanism just described, ding wheel 210 to be swung up and down about the pivot pin 218.

The cam 232 consists of a ring of flexible metal, such as thin steel, which is supported around this screw 354 being'V 21() may be its periphery, though 1n position not to interferewiththe roller 231, such clamps 233 gripping both the inner and outer edges of the metal ring and being supportedon the upper ends of screws 234 carried by a stiff -annulus 235 which has the approximate general shape which the ring 232 should have and is supported on a hollow column 236 through which the shaft 226 extends and in which it has its upper bearing. By turning kthe various screws 234, the cam shape of the ring 232 can be adjusted as desired, to vary the relative times. and speeds of different parts of the up and down movement of the grinding wheel 210 about the pivot pin 218.v In order that this up and down movement ofthe grinding wheel may act properly, on

'the saw teeth, it is necessary that the saw teeth be fed forward under the grinding wheel. This is done by means of a pair of feed fingers 241 and 242, carried by two 'arms 243 and 244 respectively and-spaced justed position on the arms 243 by a nut.

248 lon the upper end of the stud 2.46. By reason of the slight difference in the spacing .between the feed iingers241 and 242 and,-

the spacing between adjacentsaw teeth, the feeding operation of the feed fingers as they are reciprocated as later described tends to smooth out any inequalities which may exist in the spacing of the saw teeth, for when a normal or a narrow space is reached the finger 242 operates on the saw and causes a normal or greater than normal grinding of the tooth, while when a wider space is reached the feeding is done by the finger 241 and causes a less heavy grinding of the tooth.

. The arm 243 is pivoted on the arm 244 on an adjustable pivot pin 255, which furnishes another, though less delicate means for adjusting the distance between feed fingers '241 and 242. The arm 244 at its right hand end is provided with a trunnion 256 which rotatably ts within a slide .block '257, mounted within a slideway 258 and held therein by' apin 259 and a plate 260 which bears against the opposite side of the slideway from that against which the arm 244 bears, as shown in Fig. 20; The' slide block 257 is adjustable along the slideway 258 by a screw 261, conveniently connected by bevel gearing 262 to an operating shaft and wheel 263.

The slideway 258 forms the upper end of a lever 265, which is pivoted in the frame the lower end of such lever beingpivotally connected to one end of a link 266 the other end of which is pivoted to a slide block 267 slidable along a slot 268 in a pivoted arm 269, the sliding of the block 267 along' the slot 268 being obtained by an adjusting screw 270. The free end of the arm 269 is provided with a finger 271 which bears against a cam 272 fixed on the shaft 46', so that when such shaft is rotated. the arm 269 and the lever 265 are swung about their vided by the gage block 275, which is slidablelongitudinally along the frame 30 vby a screw 276 to coperate with the free end of the arm 244. l

The free ends of the arms 243 and 244 are broadened to provide heads 277 and 27 8,' .which slide along slide bars 279 fastened to the upper edge of the frame 30 on the two sides of the slot through which the arms 243 and 244 project upward, and these heads are provided with rollers 280 on the side away from the saw, these rollers coperating-with a horizontally extending slide bar feed fingers above and clear of the lsaw teeth vor to allowsuch feed ngers to drop into'engagement with the saw teeth, the verticallmovement of this slide bar 281 here. being obtained by connecting it by -a vertical bar 282, conveniently integral with the bar 281, to a hand lever 283 which can be swung up and down around a horizontal pivot, a suitable nger 284 being provided for holding the lever 283 in its upper position.

281 which is movable vertically to lift thel When the grinder is operating, which it does when the clutch 51 is in clutching position, the feed fingers are reciprocated as above describedto feed the saw forward a tooth at a time, and. at the same time, bythe operation of theroller 231 on the adjustable cam 232, the grinding wheel 210 is swung up and down around the pivot pin 218. Bv-

proper adjustment of the cam 232, the relative movement ofthe grinding wheel 210 up and down and the feeding of the-saw forward by the feed fingers 241 and 242 may be l made such that the grinding wheel follows closely the shape of the saw tooth, the saw remaining substantially stationary as the grinding wheel starts downward and grinds the face of the tooth and being moved forward rst slowly and then more rapidly as.

the grinding wheel goes down into the throat 

